Piston Wash Pics 6500 miles T-Cat

[feelthethunder]

I thought I would change my top end on my reliable 02 T-Cat for the first time.

I need some insight as to what was happening here
2002 T-Cat, vforce3, 2 degree key, BM pipes (ceramic coated), 340 MJ fourth needle clip stock air, stock can, Castrol oil for 5000 miles, last 1000 was Shell
6500 original miles, pipes installed for 4500 miles
Lots of top end lake running and also lake cruising at 70-80 hard pack, -5C to -20C 1200 ft. elevation
Top speed was 118 mph on gps

One thing I did different recently was to move the needle clip to the third position the last 700 miles, it was just using too much fuel and I couldn’t make it to gas stations.

Any of my other stock piped T-Cats looked similar except for the brown, and the attempted hole, in the center of the pistons. Also my center pipe had a hole in it closer to the can end. It was covered pretty well from the PTO pipe though.

Black Magic’s recommendations were 340 MJ and the clip in the fourth position. It’s looking like they were pretty correct.

I have looked at my wash before and I have never noticed those brown spots/hole. Could moving the clip the last 700 miles cause this or maybe the ceramic coated pipes? Was this happening at midrange or full throttle?

[bikeme2001]

Im running 410s on my t cat with stock everything except air box.The boots that go to the carbs were junk so I use uni filters with outer wears pre filters and a tempa flow.

[bjankuski]

My guess is this happened at mid range and is because you moved the clips to the 3rd spot from the 4th. T-cats are very lean in the mid range, expecially with a 340 MJ.

[triple air 1000]

Not to mention how lean a timeing key makes the midrange.

[tcat446]

I run mine in the 4th position. I have 430's across the board for jetting. (I'm at 1250 ft above sea level) 340 sounds lean to me. I have the Black Magic pipes ceramic coated as well, v-force 3 reeds, 01 ignition and no timing key.
The center looks like it was starting to melt at one point or another if you blow up the pic.

[fijjity]

agree with the midrange keyway and clip movement.
All looks good to me. No telling what % of running where caused what.
Fix the pipes, use a better injection oil.
What plugs are you running?

[feelthethunder]

I am running br9eya.
I have never seen such happy pistons, except for the holes, so I don't think oil is an issue, the skirts and sides on both the intake and exhaust side are immaculate especially for 6500 miles. I will not use synthetic oil. There is next to no sandblasting on the edges of the domes. This is an 02 so the pistons were coated from factory, I don't know if that makes a difference but I bought the coated ones for the rebuild. I honed the cylinders for 30 seconds and they look like new.

I have been told for years that 340's are too lean. I am just going by what was recommended by Black Magic. I run 320's, 3rd clip, in my stock piped 00 T-Cat with a 2.5 key and 01 ignition and 300's in my wife's 01 Pantera with no problems, nice black domes with a little wash at 4 spots. pics included.

I would guess this happened from moving my clips. It seems there was carbon in the centers and it has been burned off. I think I will put the clip back to the 4th position and cave in and run a 1 size richer jet in the center. The center piston was obviously getting hotter. I bought some tempa flows so maybe my fuel range will be better.

[dynocat]

your piston would have been problably perfect without the 2.5 timing key....remember that black magic was recommending exactly what you"ve done. increasing 20 in main jet with needle clips in 4th positions...this sled came with 320 in jet size,and even there they where already on the rich side from artic factory!! i still don"t understand why guy over here drown them with the 400/500 size??

put out your v-force...for a somebody who like high speed like you seem, they"re just useless!! these v-force are just good for accelerations race..{600 feet} and for modified engine who run around 9000 rpm!!they dont give any additional horsepower on the top on trail machine

take it or leave it...been there, done that

[gus bohne]

Look for any thing that might be making the cnter have a wisper of an air leak.

the pistons look wonderfull to me. yes it hurt the center a touch but Imy opinion it was NOT mid but at wideopen.. When we se mid damage it usually shows on the exhaust edge as well.. smearing and sticking the piston rings..

When I see the dead center get it , reminds me of my old 900 and the time I tried venting to the airbox like a poohog...well one hard run down the lake and she shut offf ! oops tailight fuse LOL.. that was a leanout due to the vneting change.. yours looks like a slight lean issue that would make me do a vigorous search for a slight airleak or go up 1 size on the center..

its not uncommon for me to stagger needle setting on my triple cats.. always the cneter is 1 cip richer than the others.. I feel the pipe being heated by the other 2 pipes ( bologna between 2 slices of bread theory ) makes it look for a wisker more fuel on long runs...

Even at dynotech I run the center richer and every looks wonderfull..

all in all, good looking pistons.

gus

[bikeme2001]

Originally Posted by dynocat

your piston would have been problably perfect without the 2.5 timing key....remember that black magic was recommending exactly what you"ve done. increasing 20 in main jet with needle clips in 4th positions...this sled came with 320 in jet size,and even there they where already on the rich side from artic factory!! i still don"t understand why guy over here drown them with the 400/500 size??

put out your v-force...for a somebody who like high speed like you seem, they"re just useless!! these v-force are just good for accelerations race..{600 feet} and for modified engine who run around 9000 rpm!!they dont give any additional horsepower on the top on trail machine

take it or leave it...been there, done that

When I installed my Tempa Flow , I read the instructions and it said to jet for a topend run on the coldest temp you would run. I had 330s and the sled was too lean. went to 350s and too lean. I continued until I felt safe. The thing is great on fuel and responsive in the trails. The Tempa Flow takes care of the mid range. 410s work for me.
Now the reason I had the 330s in was cuz I had a stock air box and the boot to the carb from the airbox was junk. I installed uni filters with pre filters and thought it would be fine. The air box is there without the boot. Trail rode it and never did a high speed test run. Very suprised at how lean that sled was after all the talk about open airboxes sucking hot engine compartment air and how pig like they run.
V force useless? Throttle responce is better isnt it? I dont have them on this sled but have used them in the past. I thought the mid range was way better.Got rid of that flat spot that the stockers have.